In a moment, I will bring you up to date with regard to my experiments, but first feast your eyes on this YouTube video, which we took just a few minutes ago as I virtually pen these words:

Now, just to make sure we're all tap-dancing to the same drum beat and humming to the same bagpipe riff, let's remind ourselves that the Prognostication Engine combo is going to comprise two units, as illustrated below:

The Inamorata Prognostication Engine is to be presented in the antique 1929 radio cabinet at the bottom. Gracing the front of this cabinet will be two brass control panels festooned with antique knobs and switches and meters and suchlike -- one in the big rectangular area at the top and the other in the interestingly shaped area underneath.

Meanwhile, the Ultra-Macho Prognostication Engine will be presented in an antique-looking box that sits on top of the radio cabinet (just a crude mock-up of this box is shown in the image above). This unit will have one brass panel in the front (shown in white in the image), where this panel will be a slightly larger version of the equally eye-catching lower panel in the bottom cabinet.

Sitting flat on the top of the left-hand side of the upper cabinet will be yet another brass panel, and mounted on this will be my antique vacuum tubes. Once again, the ones shown above are an early mockup. I've since tracked down some really great tubes, which we shall consider in more detail momentarily.

@David: I love the rotation effect in the video, it looks too smooth to be discrete leds - how many LEDs are there?

There were 13 LEDs in this case, because I was using the Adafruit NeoPixel strip with 60 LEDs per meter -- but I'm also going to try the 144 LEDs/Meter strip from Adafruit, which should give me about 30 LEDs around the base of the big tube!!!

@bert22306: Or is it as I expected, that the cathode just isn't boiling off any electrons? Quel dommage!

What a pity indeed -- but we are still at the beginning of the experiments -- someone suggested that the yellow hue to one of the tubes might signify that it would fluoresce if exposed to a UV LED (I didn't even know they made UV LEDs). For tubes with cathodes I expect to make them glow -- someone else suggested that one of the tubes might be some sort of rectifier that could be made to act a bit like a fluorescent tube ... lots to think about here...

I like the effect more with the light bulb than with the tube Max. Maybe because the tube structures are mostly in the same plane that the LEDs are shining, hence don't get much direct illumination? I'm also sure that the pics/videos dont do them justice, I know these things are VERY difficult to photograph.

I love the rotation effect in the video, it looks too smooth to be discrete leds - how many LEDs are there?

Wait. I thought you had replaced the rather staid and boring heaters with colorful LEDs, and were going to show us some fantastic impact of this on the characteristic curves of antique tubes. No? Or is it as I expected, that the cathode just isn't boiling off any electrons? Quel dommage!